Robust H∞ control of single input-delay systems based on sequential sub-predictors

• Published in: IET control theory & applications 2014-09, Vol.8 (13), p.1175-1184
• Main Authors: Najafi, Majdeddin, Sheikholeslam, Farid, Wang, Qing-Guo, Hosseinnia, Saeed
• Format: Article
• Language: English
• Subjects: control system synthesis; dead‐time systems; delay systems; disturbance propagation; H∞ control; H∞ state predictor; linear input‐delay systems; linear systems; prediction error; robust control; robust H∞ control; sequential sub‐predictors; single input‐delay systems; SSP method
• ISSN: 1751-8644; 1751-8652; 1751-8652
• DOI: 10.1049/iet-cta.2012.1004

This study presents an approach to the H∞ control of linear input-delay systems. First, an H∞ state predictor is introduced for dead-time systems with disturbance input and measurable outputs. The author's proposed method focuses on optimisation of the disturbance propagation in sequential sub-predictors (SSP). Each of the predictors is employed to forecast the state for one portion of the delay. The H∞ performance of the prediction error can be improved by increasing the number of predictors. Consequently, an H∞ controller is designed for the standard H∞ problem of dead-time systems using SSP. More importantly, the SSP method is extended to the robust H∞ control in presence of uncertainties. Some examples are given to illustrate the effectiveness of proposed method.